When Dairy Intolerance Joins Celiac Disease

It was the itch that wouldn’t quit. Melinda Dennis had developed a painful skin rash that turned out to be dermatitis herpetiformis, a sure sign of celiac disease.

But this was 1990 and back then so little was known about celiac disease and its symptoms that Dennis thought she’d just picked up the nasty rash from a germ-infested yoga mat. She then got the proper diagnosis and began the long journey of teaching herself about the foods that contain gluten, a protein in wheat, barley and rye products, which her immune system treats like an invading enemy.

Dennis learned to scour ingredients labels on foods and to be diligent eating outside her home. With vigilance, the rash soon disappeared. It was reasonable to assume that the gastric symptoms – bloating and alternating diarrhea or constipation – would go away, too. But oddly, they didn’t.

Dennis, who was 25 at the time, knew that she’d worked hard to be gluten-free – it had to be something else. She squared her shoulders and began to experiment, eating small amounts of different foods to gauge her body’s responses. Dairy was definitely causing her to feel bloating. It turned out that, along with celiac disease, she’d become lactose intolerant, which meant she was unable to properly digest the sugar found in dairy products.

“I could eat yogurt and get away with hard cheeses,” says Dennis, a dietitian who holds a Master of Science in nutrition and health promotion and helped to found the celiac center in 2004 at Boston’s Beth Israel Deaconess Medical Center. But in those early months, Dennis had to cut most dairy products out of her diet.

She is not alone. One out of every 100 people in North America is thought to have celiac disease while Dr. Peter Green, the director of the Celiac Disease Center at Columbia University, says that between 10 to 20 per cent of those with the autimmune disease also have differing degrees of lactose intolerance – creating a double diet whammy to manage.

Gluten’s Internal Toll

While research on the relationship between celiac disease and lactose intolerance is scant, an intriguing Italian study was published in the journal Digestion in 2005. In it, researchers screened 54 people who had tested positive for lactose intolerance but showed no other symptoms for celiac disease, and a control group of 50 blood donors.

Those who had the antibodies associated with celiac disease underwent further intestinal biopsies to see if there was damage to the villi, the finger-like projections that line the intestinal wall and act as gatekeepers for nutrients to enter the body.

The findings were startling: 24 per cent of the patients with lactose intolerance had damaged or atrophied villi, a sure sign of celiac disease, compared to a mere 2 per cent of the control group. Today, Dr. Peter Green says there’s a “very sensible recommendation” that all patients who test positive for lactose intolerance should be examined further for celiac disease before they are placed on a dairy-free diet.

He is concerned, however, that too many doctors and dietitians automatically advise lactose intolerant patients to avoid dairy – a kneejerk response that fails to take into account that celiac disease may be the real culprit.

By shortening or completely flattening the villi, celiac disease disrupts the uptake of life-sustaining nutrients, and can lead to other serious conditions – from malnutrition to anemia, osteoporosis and even cancer. The villi also contain lactase, the enzyme necessary to process lactose, the sugar in dairy. So when the villi are damaged, dairy intolerance is often the result.